JPS6012497B2 - Connection structure between pile cap and footing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to, for example, a joint structure between a concrete pile and a footing.

In recent years, the extent of damage to the heads of concrete piles caused by earthquakes has become clearer, and it has been discovered that the damage is greater than expected, and countermeasures are urgently needed.

Traditionally, there have been two methods of connecting piles and footings: a fixed method and a hinge method.If there is margin for horizontal displacement of the structure during an earthquake, the hinge method reduces the bending moment applied to the pile by 4. This is advantageous in terms of design.

By the way, in the conventional hinge connection method, the embedded length of the head of the pile in the footing is shortened by, for example, 10 to 15 degrees, and hinge reinforcing bars are used if necessary.

However, even if hinge reinforcement is used to connect the pile footing,
During an earthquake, a bending moment that exceeds the design calculation value is generated in the pile, and because the structure is incompletely hinged, when the horizontal displacement of the structure becomes large, the footing in contact with the pile may partially break. Ta. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a connection structure that prevents bending moment from occurring in the pile cap through ideal complete hinge connection.

An embodiment of the present invention will be explained based on the drawings. In Fig. 1, the pile cap of the concrete pile 1 is first treated, and the main reinforcements 2,
Issue...

Therefore, after pouring concrete into the head of the pile 1, the hinge 3 is fitted together. The lower hinge 3 is cap-shaped,
Since main reinforcement fastening holes 4, . . . , into which the main reinforcements 2, . A sphere 5 is integrally formed and protrudes from the center of the upper surface of the lower hinge 3. Therefore, the upper hinge 6 and the lower hinge 3 are freely connected, but the upper hinge is divided into left and right halves as shown in the second figure.
An inner arc-shaped hole 7 is formed on the lower surface of the center to be iron-coupled with the sphere 5 of the lower hinge. After aligning the holes from the left and right sides of the sphere, the joint flange 8 is secured with a tightening fitting 9. The upper hinge 6 is integrated.

As shown in FIG. 2, a plurality (three) of the fastening metal fittings 9 are used to strengthen the fastening. At this time, in order to improve the stability of the upper hinge 6, it is desirable to interpose a piece of wood (not shown) between the upper hinge and the upper surface of the lower hinge 3. Further, on the upper surface of the upper hinge 6, the lower ends of fixing lines 10, which are arranged in a circular shape as shown in the second figure, are welded. Next, a protective member 11 is attached to the space between the upper hinge 6 and the lower hinge 3 to prevent cement and soil, which will be discussed later, from entering.

This protective member 11 is made by attaching, for example, a PVC pipe cut in two to a predetermined position, and then joining and bonding them together with an adhesive.
Thereafter, the excavated soil is backfilled, broken stones 12, . Since the present invention has the above configuration, the bending moment generated at the head of the pile can be reduced to zero, significantly improving the reliability of the pile, and it is safe because no bending moment is generated due to differences in the assumption of connection conditions during an earthquake. Does not cause partial destruction of footings, etc.

Since the main reinforcement of the pile is used for the pile and the lower hinge, the structure of the connecting means is simple. The upper hinge fixes the anchorage,
Since a rising edge is provided around the outer circumference of the footing to surround the anchorage bar, it is possible to ensure that the footing is integrated with the concrete.
Furthermore, it can sufficiently handle the tensile force created in the piles and foundations.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view, and FIG. 2 is a sectional view taken along line D--B in FIG. 1. 1... Pile, 2... Main reinforcement, 3... Lower hinge, 5... Sphere, 6
...Top hinge, 10...Fixing line, 11...Protective member. Heron Figure 1 Figure 2

Claims (1)

[Claims] 1. A lower hinge that fits into the pile head and fixes the pile main reinforcement,
An upper hinge that is hinged to this lower hinge,
A protective member is provided between the upper hinge and the lower hinge to prevent the intrusion of concrete, etc., and the upper hinge is split into two parts, with fixing bars fixed to the upper surface and the fixing bars attached to the outer periphery. A joint structure between a pile cap and a footing, characterized by having a surrounding rising edge.